void main()
{
int cx, cy, rx, ry;
printf("Enter the center ");
scanf("%d%d", &cx, &cy);
printf("x radius : ");
scanf("%d", &rx);
printf("y radius : ");
scanf("%d", &ry);
long rx2 = (long) rx * rx;
long ry2 = (long) ry * ry;
long trx2 = 2 * rx2;
long try2 = 2 * ry2;
long p, x = 0, y = ry;
long px = 0;
long py = trx2 * y;
p = (long) ((ry2 - (rx2 * ry) + (0.25 * rx2)) + 0.5);
int gd = DETECT, gm = DETECT;
initgraph(&gd, &gm, "");
cleardevice();
putpixel(cx, cy, 15);
while (px < py) {
plotpoints(cx, cy, x, y);
x++;
px += try2;
if (p < 0)
p += ry2 + px;
else {
y--;
py -= trx2;
p += ry2 + px - py;
}
}
py = trx2 * y;
px = try2 * x;
p = (long) ((ry2 * (x + 0.5) * (x + 0.5) + rx2 * (y - 1) * (y - 1) - rx2 * ry2) + 0.5);
while (y >= 0) {
plotpoints(cx, cy, x, y);
y--;
py -= trx2;
if (p > 0)
p += rx2 - py;
else {
x++;
px += try2;
p += rx2 - py + px;
}
}
getch();
}
void bellipse(int xc, int yc, float r1,float r2)
{
float p, slope=0, sqr;
int x, y, lasty;
if (r1!=0)
sqr=(r2*r2)/(r1*r1);
else
return;
p = 2*sqr-2*r2+1;
x = 0;
y = r2;
while(y && slope>-1)
{
plotpoints(xc,yc,x,y);
if (p<0)
p+=4*sqr*x+6*sqr;
else
{ p+=4*sqr*x-4*y+6*sqr+4;
y--;
}
x++;
if(y==0 || sqr==0) return;
slope=(float) x/y*sqr*(-1);
}
lasty=y, y=0, x=r1;
if (r2!=0)
sqr=(r1*r1)/(r2*r2);
else
return;
slope=-2;
p=2*sqr-2*r1+1;
while(x && y<=lasty)
{
plotpoints(xc,yc,x,y);
if (p<0)
p+=4*sqr*y+6*sqr;
else
{ p+=4*sqr*y-4*x+6*sqr+4;
x--;
}
y++;
}
}
